OK call me a dumbarse but I can't find the method of adding an attachment that used to be here. ?Here is the info copied and pasted from GM SI.
Document ID # 1234118
2003 Chevrolet Avalanche - 2WD ?
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Whine Noise From Rear Axle (Diangose and Replace Rear Shaft With A Tuned Torsional Damper Rear Propeller Shaft) #03-04-17-001 - (01/30/2003)
Whine Noise From Rear Axle (Diagnose and Replace Rear Shaft With A Tuned Torsional Damper Rear Propeller Shaft)
2002-2003 Cadillac Escalade EXT
2000-2003 Chevrolet Suburban
2002-2003 Chevrolet Avalanche
2000-2003 GMC Yukon XL, Yukon XL Denali
Condition
Some customers may comment on a slight axle whine heard only at certain speeds, typically between 72-96 km/h (45-60 ?mph).
Cause
"Inherent" ring and pinion gear whine.
All gear driven units, such as automotive rear axles, produce some level of noise that cannot be eliminated with conventional adjustments and repairs. "Inherent" axle noise can be described as a slight noise heard only at a certain speed (typically between 72-96 km/h (45-60 mph) on most General Motors? trucks). The presence of this noise is not indicative of a functional concern with the axle assembly. However, some customers may find that this "inherent" axle noise is unacceptable.
Correction
Replace the rear propeller shaft with a tuned torsional damper shaft ONLY after diagnosis concludes that it is an "inherent" rear axle noise and no physical damage or incorrect adjustment exists.
Important
If the noise is not correctly diagnosed as "inherent" and having a peak in the narrow speed range of 72-96 km/h (45-60 mph), the addition of a tuned torsional damper propeller shaft can aggravate the perceptible noise level. It is extremely important to first diagnose the rear axle noise as "inherent" before installing a new tuned torsional damper propeller shaft.
Diagnostic Information and Procedure for Rear Axle Noise
Diagnostic Starting Point - Rear Drive Axle. Refer to SI Document ID #696972.
Symptoms - Rear Drive Axle. Refer to SI Document ID #697220.
Rear Drive Axle Noises. Refer to SI Document ID #700580.
Noisy in Drive. Refer to SI Document ID #698120.
Rear Propeller Shaft Replacement
Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Refer to SI Document ID #737171.
Remove the bolts and the yoke retainers from the rear axle pinion yoke.
Notice
When removing the propeller shaft, do not attempt to remove the shaft by pounding on the yoke ears or using a tool between the yoke and the universal joint. If the propeller shaft is removed by using such means, the injection joints may fracture and lead to premature failure of the joint.
Slide the propeller shaft forward in order to disconnect the propeller shaft from the rear axle pinion yoke.
Slide the propeller shaft rearward in order to disconnect the propeller shaft from the transmission or transfer case.
Remove the propeller shaft from the vehicle and discard.
Install the new tuned torsional damper propeller shaft (see Parts Information below) into the transmission or transfer case.
Install the propeller shaft to the rear axle pinion yoke.
Install the yoke retainers and bolts. Tighten
Tighten the yoke retainer bolts to 25 N?m (19 lb ft).
Lower the vehicle.
Road test the vehicle.
Parts Information
Important
Only small quantities of parts are available. Please DO NOT order for stock only.
Part Number
Description
15075236
Rear Prop Shaft with Tuned Torsion Damper (2WD Suburban, Avalanche, Yukon XL)
15767178
Rear Prop Shaft with Tuned Torsion Damper (4WD Suburban, Avalanche, Yukon XL and 2003 only AWD Yukon XL Denali, Escalade EXT, with NR3 Transfer Case)
15064596
Rear Prop Shaft with Tuned Torsion Damper (2001 and 2002 only AWD Yukon XL Denali, Escalade EXT with NP3 Transfer Case)
Parts are expected to be available from GMSPO on February 17, 2003.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation
Description
Labor Time
F1280
Propeller Shaft Assembly (Rear) - Replace
Use published labor operation time
Add A
Diagnosis Time
0.0-0.3 hr
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information. ?WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
? Copyright General Motors Corporation. All Rights Reserved.
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?Document ID # 1234118
2003 Chevrolet Avalanche - 2WD